<!doctype html>
<html>
    <head>
        <meta charset="utf-8">
        <title>Random Flow - ECHARTS-GL</title>
        <meta name="viewport" content="width=device-width, initial-scale=1, user-scalable=no">
        <meta name="apple-mobile-web-app-capable" content="yes"> <!-- Fullscreen Landscape on iOS -->
        <link rel="stylesheet" href="./common.css">
    </head>
    <body>
        <div id="main"></div>
        <script src="../node_modules/echarts/dist/echarts.js"></script>
        <script src="../dist/echarts-gl.js"></script>
        <script src="lib/jquery.min.js"></script>
        <script src="lib/simplex.js"></script>
        <script src="js/commonUI.js"></script>
        <script>
            var chart = echarts.init(document.getElementById('main'));

            var noise = new SimplexNoise(Math.random);
            var noise2 = new SimplexNoise(Math.random);
            function generateData() {
                var data = [];
                for (var i = 0; i <= 50; i++) {
                    for (var j = 0; j <= 50; j++) {
                        var dx = noise.noise2D(i / 30, j / 30);
                        var dy = noise2.noise2D(i / 30, j / 30);
                        var mag = Math.sqrt(dx * dx + dy * dy);
                        valMax = Math.max(valMax, mag);
                        valMin = Math.min(valMin, mag);
                        data.push([i, j, dx, dy, mag]);
                    }
                }
                return data;
            }
            var valMin = Infinity;
            var valMax = -Infinity;
            var data = generateData();

            chart.setOption({
                visualMap: {
                    show: false,
                    min: valMin,
                    max: valMax,
                    dimension: 4,
                    inRange: {
                        color: ['#313695', '#4575b4', '#74add1', '#abd9e9', '#e0f3f8', '#ffffbf', '#fee090', '#fdae61', '#f46d43', '#d73027', '#a50026']
                    }
                },
                xAxis: {
                    type: 'value',
                    axisLine: {
                        lineStyle: {
                            color: '#fff'
                        }
                    },
                    splitLine: {
                        show: false,
                        lineStyle: {
                            color: 'rgba(255,255,255,0.2)'
                        }
                    }
                },
                yAxis: {
                    type: 'value',
                    axisLine: {
                        lineStyle: {
                            color: '#fff'
                        }
                    },
                    splitLine: {
                        show: false,
                        lineStyle: {
                            color: 'rgba(255,255,255,0.2)'
                        }
                    }
                },
                series: [{
                    type: 'flowGL',
                    data: data,
                    particleDensity: 64,
                    particleSize: 5,
                    itemStyle: {
                        opacity: 0.5
                    }
                }, {
                    type: 'custom',
                    data: data,
                    encode: {
                        x: 0,
                        y: 0
                    },
                    renderItem: function (params, api) {
                        var x = api.value(0), y = api.value(1), dx = api.value(2), dy = api.value(3);
                        var start = api.coord([x - dx / 2, y - dy / 2]);
                        var end = api.coord([x + dx / 2, y + dy / 2]);
                        return {
                            type: 'line',
                            shape: {
                                x1: start[0], y1: start[1],
                                x2: end[0], y2: end[1]
                            },
                            style: {
                                lineWidth: 2,
                                stroke:'#fff'
                            }
                        }
                    }
                }]
            });

            window.onresize = chart.resize;
        </script>
    </body>
</html>